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<TITLE>[Chapter 20] 20.3 java.awt.event.AdjustmentEvent (JDK 1.1)</TITLE>
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<h2 CLASS=sect1><A CLASS="TITLE" NAME="JNUT2-CH-20-SECT-3">20.3 java.awt.event.AdjustmentEvent (JDK 1.1)</A></h2>

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<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-20-SECT-3.1"></A></h3>
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<P CLASS=para>
An event of this type indicates that an adjustment has been
made to an <tt CLASS=literal>Adjustable</tt> object--usually, this means
that the user has interacted with a <tt CLASS=literal>Scrollbar</tt>
component.  

<P CLASS=para>
The <tt CLASS=literal>getValue()</tt> method returns the new value
of the <tt CLASS=literal>Adjustable</tt> object.  This is usually the most
important piece of information stored in the event.
<tt CLASS=literal>getAdjustable()</tt> returns the <tt CLASS=literal>Adjustable</tt>
object that was the source of the event.  It is a convenient
alternative to the inherited <tt CLASS=literal>getSource()</tt> method.

<P CLASS=para>
The <tt CLASS=literal>getID()</tt> method returns the type of an
<tt CLASS=literal>AdjustmentEvent</tt>.  The standard AWT components only
generate adjustment events of type
<tt CLASS=literal>AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED</tt>.  
There are
several types of adjustments that can be made to an
<tt CLASS=literal>Adjustable</tt> object, however, and the
<tt CLASS=literal>getAdjustmentType()</tt> method returns one of five
constants to indicate which type has occurred.
<tt CLASS=literal>UNIT_INCREMENT</tt> indicates that the <tt CLASS=literal>Adjustable</tt>
value has been incremented by one unit, as in a
scroll-line-down operation.  <tt CLASS=literal>UNIT_DECREMENT</tt>
indicates the opposite: scroll-line-up.
<tt CLASS=literal>BLOCK_INCREMENT</tt> and <tt CLASS=literal>BLOCK_DECREMENT</tt> indicate
that the <tt CLASS=literal>Adjustable</tt> object has been incremented or
decremented by multiple units, as in a scroll-page-down or
scroll-page-up operation.  Finally, the <tt CLASS=literal>TRACK</tt>
constant indicates that the <tt CLASS=literal>Adjustable</tt> value has
been set to an absolute value unrelated to its previous
value, as when the user drags a scrollbar to a new
position.

<DIV CLASS=screen>
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<PRE>
public class <tt CLASS=literal>AdjustmentEvent</tt> extends AWTEvent {
    // <tt CLASS=literal>Public Constructor</tt>
            public <tt CLASS=literal>AdjustmentEvent</tt>(Adjustable <tt CLASS=literal>source</tt>, int <tt CLASS=literal>id</tt>, int <tt CLASS=literal>type</tt>, int <tt CLASS=literal>value</tt>);
    // <tt CLASS=literal>Constants</tt>
            public static final int <tt CLASS=literal>ADJUSTMENT_FIRST</tt>;
            public static final int <tt CLASS=literal>ADJUSTMENT_LAST</tt>;
            public static final int <tt CLASS=literal>ADJUSTMENT_VALUE_CHANGED</tt>;
            public static final int <tt CLASS=literal>BLOCK_DECREMENT</tt>;
            public static final int <tt CLASS=literal>BLOCK_INCREMENT</tt>;
            public static final int <tt CLASS=literal>TRACK</tt>;
            public static final int <tt CLASS=literal>UNIT_DECREMENT</tt>;
            public static final int <tt CLASS=literal>UNIT_INCREMENT</tt>;
    // <tt CLASS=literal>Public Instance Methods</tt>
            public Adjustable <tt CLASS=literal>getAdjustable</tt>();
            public int <tt CLASS=literal>getAdjustmentType</tt>();
            public int <tt CLASS=literal>getValue</tt>();
            public String <tt CLASS=literal>paramString</tt>();  //<tt CLASS=literal> Overrides AWTEvent</tt>
}
</PRE>
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<DIV CLASS=sect2>
<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-20-SECT-3.2">Hierarchy:</A></h3>

<P CLASS=para>
<tt CLASS=literal>Object->EventObject(Serializable)->AWTEvent->AdjustmentEvent</tt>

</DIV>

<DIV CLASS=sect2>
<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-20-SECT-3.3">Passed To:</A></h3>

<P CLASS=para>
<tt CLASS=literal>AdjustmentListener.adjustmentValueChanged(), 
AWTEventMulticaster.adjustmentValueChanged(), 
Scrollbar.processAdjustmentEvent()</tt>

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